1. Field of the Invention
The present invention relates to car dumpers, and, more particularly, to a car dumper suitable to pass the engine of a unit train, or any engine or oversize car.
2. Description of the Prior Art
Generally, a railroad car dumper has a frame which is rotatable about a longitudinal axis. The dumper has tracks to receive a car to be dumped from adjacent tracks. It has long been known to mount the tracks in the dumper on a carriage which is shiftable laterally to move the car against a supporting sidewall in the dumper as the dumper rotates. With this type of dumper (shown, for example, in U.S. Pat. Nos. 1,770,175 and 3,373,829), the car or cars being dumped were separated from the remaining cars of the train before dumping.
With the advent of unit trains (that is, trains made up of a single type of car carrying a single product) and rotary couplers (that is, couplers which permit a car to be rotated about the longitudinal axis of the couplers while connected to a car which is not being rotated), it became desirable to pass the entire train in steps through the dumper, dumping one or more cars at a time without detaching the dumped cars from the adjacent cars outside the dumper. A dumper for this type of operation is shown in U.S. Pat. No. 3,275,169.
With the unit train, it is convenient to have the engine pass through the dumper first, and pull the cars of the train behind. It should be noted that whenever a car with rotary couplers is to be dumped (whether or not the car is a part of a unit train) without uncoupling from adjacent cars which are not to be dumped, the car couplers must remain substantially on the axis of rotation of the dumper. Since the sidewall in the dumper frame supports the car during dumping, and the car must enter the dumper on the axis of rotation of the dumper and remain on said axis, a problem of clearance of the sidewall will arise if the car is oversize, or if the engine must pass through the dumper. It should be noted that the problem of clearance of the sidewall can arise even if the train is not a unit train and even if the cars are not to remain coupled during dumping. In other words, even when the carriage supporting the tracks in the dumper is shiftable toward and away from the sidewall, a problem of clearance of an engine can arise.
In the U.S. Pat. No. 3,275,169, the problem of clearance is solved by providing a supporting sidewall which is movable in the frame up to the side of the car and away from the side of the car to provide alternatively support for the car, and clearance for passage of an engine or a wider car. Other patents showing movable car supports in the frame include U.S. Pat. No. 603,336; U.S. Pat. No. 758,191; U.S. Pat. No. 1,286,504; U.S. Pat. No. 1,440,888; U.S. Pat. No. 1,501,879; U.S. Pat. No. 1,846,970; U.S. Pat. No. 2,054,199; U.S. Pat. No. 2,542,660; U.S. Pat. No. 3,082,888; German Pat. No. 971,736; German Pat. No. 1,069,073; and German Pat. No. 1,143,146.